Search crews lowered by ropes from helicopters through dense jungle searched the wreckage of a Brazilian jetliner that apparently clipped an executive jet and slammed into the ground in the Amazon rain forest, likely killing all 155 people aboard.
It would be Brazil's worst air disaster if all 149 passengers and six crew aboard Gol airlines flight 1907 are confirmed dead. The jungle where the Boeing 737-800 went down is so dense that crews had to cut down trees on Saturday to clear a space to allow helicopters to land.
"There's little indication of survivors, but we won't rule out the possibility," Brazil Air Force Brigadier General Antonio Gomes Leite Filho said in a news conference. "We haven't fully explored the crash scene, it's a very complicated area."
Filho said rescue operations would continue until authorities are sure there are no survivors. The search was halted after sunset and was to resume at daybreak.
The flight vanished on Friday while flying from the jungle city of Manaus to Brasilia and Rio de Janeiro. Searchers located the wreckage on Saturday.
Brazilian President Luiz Inacio Lula da Silva declared three days of mourning for victims of the crash, which cast a cloud over preparations for the country's presidential election yesterday.
The president of Brazil's airport authority, Jose Carlos Pereira, said the jetliner and an executive jet may have collided before the crash, though that was still under investigation.
Air force helicopter pilots hovering over the crash site saw no signs of an intact fuselage and the debris appeared to cover only a small area.
Pereira said the plane apparently hit the jungle floor at nearly 500kph, adding that "at that speed it is highly unlikely any survivors will be found."
Gol vice president David Barioni said both Brazilians and foreigners were aboard, but did not provide any breakdown.
Rescue teams reached the crash zone hours after air force helicopter pilots found the wreckage, but "so far it is impossible to confirm the existence of survivors in the area," according to a statement by the airport authority, the air force and the Civil Aviation Agency.
If no survivors are found, it would be the worst air disaster in Brazil's history, passing the 1982 crash of a Boeing 727 operated by the now-defunct Vasp airline in the northeastern city of Fortaleza that killed 137 people.
The wreckage was found near the 20,000 hectare Jarina cattle ranch, 1,750km northwest of Sao Paulo in the state of Mato Grosso.
Meanwhile, in a hotel lobby in Brasilia, some 50 weary-eyed relatives and friends of those aboard the plane waited for news of their loved ones.
"The worst thing of all is not knowing how it happened and why it happened," said Carmelita Meira, the 70-year-old grandmother of one of the passengers.